Researchers have discovered more than 111,000 spiders thriving in what appears to be the world's biggest spiderweb, deep inside a pitch-black cave on the Albanian-Greek border.

The "extraordinary" colony consists of a colossal web in a permanently dark zone of the cavern, according to a study published Oct. 17 in the journal Subterranean Biology. The web stretches 1,140 square feet (106 square meters) along the wall of a narrow, low-ceilinged passage near the entrance of the cave. It is a patchwork of thousands of individual, funnel-shaped webs, the researchers noted.

This is the first evidence of colonial behavior in two common spider species and likely represents the largest spiderweb in the world, said study lead author István Urák, an associate professor of biology at Sapientia Hungarian University of Transylvania in Romania.
https://www.livescience.com/animals/spiders/worlds-biggest-spiderweb-discovered-inside-sulfur-cave-with-111-000-arachnids-living-in-pitch-black